Brake Foot Valve, '96 Dynasty

[Joe913]

There is air escaping from the exhaust port of the foot valve while everything is off. Does anyone know what kind of valve was used for the Monaco Dynasty in 1996? Would like to know what I need before tearing down. Also, any knowledge anyone would like to share about this topic would be very helpful. Thanks

[BFlinn181]

I'd suggest removing the valve and take it to a good truck parts shop. They'll be able to match it up with a replacement or identify if it just needs to be rebuilt. On a custom chassis that's 22 years old, it would be best to have the part in hand rather than buy on someone's recommendation.

[Truckerdave]

Do you have spring parking brakes and if so are the spring brakes applied or released?

[twinboat]

There are a lot of lines and ports on a brake treddle valve. If you pull it out, take lots of pictures before you do.

I believe Truckerdave is asking if the leak happens only when the parking brake is off ( button in ) ?

Dual brake chambers ( spring brakes ) have a seal between each chamber that can leak.
If bad, air can leak out of the spring chamber, into the service chamber and flow back thru the lines and out the brake valve exhaust port. This will not happen if the parking brake is applied ( On ).

The seal is at the blue arrow.

[Joe913]

The brake valve is out--it's a Bendix E-7 288267N.

I appreciate all the input. Thanks for the info about the dual brake chambers (twinboat). I saw a Swift Transportation video discussing brake foot valves. In it the guy said a leaky brake relay valve could bleed back through the exhaust port of the foot valve.

Thanks to all for the input.